Subtracting Fractions with Unlike Denominators

The video tutorial addresses the problem of subtracting fractions with different denominators. It explains the process of finding the lowest common denominator, which is 63 in this case, and demonstrates how to convert the fractions to have this common denominator. The tutorial then shows how to subtract the fractions once they share the same denominator, resulting in the final answer of 11/63.

Why is it necessary to find a common denominator when subtracting fractions?

• To convert fractions into whole numbers

• To ensure the fractions have the same base for subtraction

• To simplify the fractions

• To make the numerators equal

What is the lowest common denominator of 7 and 9?

• 56

• 63

• 72

• 49

How do you convert 2/7 to have a denominator of 63?

• Multiply both the numerator and denominator by 9

• Multiply both the numerator and denominator by 7

• Subtract 7 from the denominator

• Add 9 to the numerator

What operation is performed to convert 1/9 to have a denominator of 63?

• Multiply both the numerator and denominator by 7

• Subtract 9 from the denominator

• Multiply both the numerator and denominator by 9

• Add 7 to the numerator

What is the result of subtracting 7/63 from 18/63?

• 11/63

• 25/63

• 5/63

• 15/63